LambdaParameterName.md

Pattern: Invalid lambda parameter name

Issue: -

Description

Checks that lambda parameter names conform to a format specified by the format property.

Examples

An example of how to configure the check is:

<module name="LambdaParameterName"/>

An example of how to configure the check for names that begin with a lower case letter, followed by letters is:

<module name="LambdaParameterName">
  <property name="format" value="^[a-z]([a-zA-Z]+)*$"/>
</module>

Example of checking with this config:

public class TestClass {

	Function<String, String> function1 = str -> str.toUpperCase().trim();

	Function<String, String> function2 = _s -> _s.trim().toUpperCase(); // violation

	public boolean testMethod(String sentence) {
		return Stream.of(sentence.split(" "))
			.map(word -> word.trim())
			.anyMatch(Word -> "in".equals(Word)); // violation
	}

}

Further Reading

• checkstyle - LambdaParameterName